Write the script for the movie. Even Hollywood filmmakers need to keep a budget in mind, so you should do the same. Create scenes that allow you to shoot outside in natural daytime light, or inside, using ambient lighting like lamps and overhead lights.
Install video capture software on your desktop or laptop computer. This software allows you to record video directly from your webcam to your computer.
Set up the scene. Position the the performers in their proper spots, allowing you the most effective shots.
Place the webcam securely in a position to capture the shot you want and plug the webcam into the computer's USB port. A stationary shot, where the camera stays in a steady position, will be less shaky than a shot where you hold the camera in your hand.
Connect a desktop microphone to your computer. This external microphone will provide the shot with better sound quality than the computer's internal microphone.
Start the video capture, following the manufacturer's instructions, and record the video to your computer using video capture software. Watch the scene play out on the computer screen as the webcam captures it. Stop the video capture at the end of the scene.
Edit the recorded video scenes together to form the movie, using the video capture software. Follow the specific instructions of the particular video capture software manufacturer.